Process and apparatus for modifying the physical characteristics of plastic materials



Dec. 2, 1952 D MAI-QSHALL 2,619,680

PROCESS AND APPARATUS FOR MODIFYING THE PHYSICAL CHARACTERISTICS OF PLASTIC MATERIALS Filed NOV. 29, 1949 2 SHEETS-SHEET 1 QZQJ. I 5

BY MQ W 12 o" j I -3 J4 g t 7 j i E A INVENTOR s2": 9 2 38 fiozmldfijvanrfiall :ggz: an),

ATTORNEYS FOR MODIFYING OF PLASTIC MA Dec. 2, E.

D APPARATUS ACTERISTICS PROCESS C ALS 2 SHEETS -SHEE Filed Nov. 29, 1949 I M M 2 n0 0 o 9.. 0 4 J, 9% w v 6 0M '6. I I 3 lllull': T llll l llllll I ll I 'l ATTORNEYS Patented Dec. 2, 1952 THE" PHYSICAL CHARACTERISTICS PLASTIC MATERIALS Dona-ME.- Marshall, Summit, N. J., assignor to Micro Processing Equipment, .Inc., Des Plaines, 111., a corporation. of Illinois Application Novemberi29, 1949, Serial No..129,942

V I82Claims.

1. This invention relates. to a .processand-apparatus for modifying the physical characteristics of plasticmaterials, and more particularly; to a process and apparatus forconVerti-ng plastic ma-' terials having acrystalline phase, :such as soap,

into: compacted ultra-microcrystalline material by subjecting them to intense shearing and compactingforces; The conversion operation may coincidentally include cooling of the material while being subjected to such-forces and either aerating or de-aerating of the resulting material.

Commercial detergent soaps-as well as certain.

other plastic materials have a solid gel structure made up of -a network of crystals, usually fibrous in nature, in which a non-crystalline material is included. Thus soap. is a two-phase-system -hav-- ing a crystalline soap phaseand aliquid-crystalline or jelly-solphase. Ordinary cooled neat soap or such soap which has been. flaked and partlyversion of the present invention cannot be obtained with milling. rollers because-of the-large clearances necessitated by mechanical consider ations. and the inability to hold the material within a confined space where such forces can be developed.

In accordance with the .presentinvention, conversion of the soap or other plastic materialis accomplished by employing a rapidly moving c'arri'er band .for drawing thinsoap films bymolecular attraction through narrow apertures or slots under tearing and dispersing conditions: to

produce intense shearing and compacting. The.

material is kept 'ina. turbulent condition inthin layers: or films on. relatively large surfaces .on

metal. members and heatfmay be rapidly with-- drawnthrough such surfaces to: provide effective temperature control Aeration of the soap during intense shearing and compacting ismade possible-by using atightly fitted chamber around the band andintroducing air or other gas into the chamber. Likewise, (is-aeration ismade possible by the exposure of large surface areas'fof th'ei material in the form of thin ribbons onflelkes 'to negative pressures developed within a chamber surroundingithe band by an exhauster;

The present inyenti'ontemploys the extraordi- The extent of particle size reduction 2" nary molecular forces which cause films toad-- here to the surface of-a-metal, such as is revealedin the soap lubrication of cold wire drawing dies, to draw the soap-film -as 'a-coating on asteehor other metal carrier band through multiple-die slots, despite strong particle shearing andcon'i pacting forces endeavoringto strip the film off the carrier band. (This surface adhesion phenomenon is fully treated'by C. J. Boner, fBetroleum' Processing, December 1948) l t-enables the use of ahigh speed-light weight steel or other metal belt or band, as'a carriermember-for scapfilms to obtain high compacting pressure and high shearing forcesin contrast to theheavystructural arrangements'of the prior art for slowly carrying; material throughthe bite of rollers. The im vention thus eliminatesmuchof the powerwas'te. and heat dissipation trouble encountered, for example, when roller mil-ling. a relatively thick soap. flake (200 microns) through the bite'o'f.'heaizy rollers in anendeavor to abrade acrystallineparticle to less than 1 micron. By reducing the flake thickness to 5 microns, for: example, as can be. done by the present invention, the required power. is largely utilized for crystal reduction and com pasting the soap. instead of being wastedibyiworking the bulk of the material unnecessarily.

Air dispersion and retention during therintm sified shearing and compacting of the. material is obtained in the present invention by. thevene trainment gas pressures developed within the close fitting die slot, and by the high speed en.- trainment action of the carrier band at-the-entrance to the slotandinsmallair chamberscommunicating with the die slot; Temperature'regulation is easily obtained byspreading. the-material out to make filmsmeasuring-about-5microns thick on elongated heat-transfer surfaces bytheme of a high speed-carrier band operating in a slot and cooling the walls of the slot or bycooling the band, or both.

As stated above, soap isa two-phasesystem' hav ng a crystalline phase of hard, less solublematerial, and a jelly phase of soft,-moresoluble material. When melted soap is solidified,large crystals form (6 to 15 microns), and these:- crystals contact each other, orare'bondedto each other by crystalline materialsothat theresulting 7 solid structure is substantially as hard as the crystalline phase-and fractures along-the crystal shear planes. When soap containing. moisture is agitated Whilecooling until'semi-fluid (say at F. for 17 moisture-soap) the-crystal sizes are reduced and if leftto set, these asmall crystals bond together with crystalline material to form a fine-grained, hard, solid structure (Bodman process). If this same soap is agitated While further solidified (say to 130 to 140 F.) the crystals are still reduced as before, and in addition, the bonds which formed between crystals in Bodmans soap are broken down, and the jelly-phase material surrounds the fine crystals, so as to give a quicker lathering bar, but a much softer and more wasteful bar (Mills process).

The cold milling on milling rolls, of soap containing the large crystals above referred to, has long been accepted as the best procedure for highgrade department store tablets. It yields a product with crystals as fine as those of Bodman or Mills (2 to 4 microns) with each crystalline particle surrounded by jell-phase material to give the quick lather of Mills process soap. However, cold-milled soaps are harder and less wasteful. Roller milling, however, has its limitations, which prevent getting crystals fine enough to produce transparency, welding properties, or the waterpenetration of a true jelly (.1 to .5 microns). Even if such fine crystals were produced, roller milling does not provide the shear compacting of such fine crystals necessary to force the crystals into contact and force the jelly-phase material into the voids between contacting crystals so as to yield a solid structure as hard as the crystalline phase material. To accomplish both the crystal size reduction and compacting of the present invention, the crystal reduction forces must be exerted on very thin layers of soap, measuring only 2 to 5 microns, in order to shear-off particles measuring .1 to .5 micron. Also, the shearing rate must be fast enough to produce fracture of these small crystals, in place of just re-arrangement. Furthermore, the compacting of crystals which are smaller than visible lights wave-length (6,000 A :.6 micron) without hav ing these particles separated from each other by soft jelly-phase material, requires a shearing action under great pressure without at the sai e time producing localized overheating sufficient to cause crystal size reversion. Certain soap milling apparatus, for example, that known as the Stacomb mill, develops crushing pressures which will reduce the size of the soap crystals below that of ordinary roller milling but in a much less efiicient manner than in the present invention because much of the power required by such apparatus is not effectively utilized. The Stacomb mill, moreover, does not provide the necessary shearing action under the required pressure to produce interlocking of the crystals of the crystal phase.

Both reduction of the soap crystals to an ultramicrocrystalline size and the application of intense shearing and compacting forces sufficient to cause interlocking of the fine crystals are required to produce a hard bar structure of ultramicrocrystalline soap. Ultra-fine crystals give bar soap better texture, transparency, toughness, and water-welding properties as well as rapid solubility to avoid overuse. Compactness gives soap a hardness which prevents disintegration into wasteful soap-dish jelly, or the wasteful sloughing off of undissolved material during the washing manipulation. That is to say, the greater solubility of the jelly phase will cause the bar to rapidly disintegrate if the crystals of the crystal phase are not interlocked.

In accordance with the present invention, the formulation employed for hard bar soaps is less critical because those animal fats, resin, vegetable and marine oils which yield the most soluble soaps and the type of lather desired, can be used Without having a soft, wasteful bar. The crystalline phase materials in various fatty acid soaps varies in hardness but substantially all such crystalline phase material is harder than necessary to give the required body to the bar, providing these crystals are interlocked, instead of being impacted in the jelly phase material. Also, the percentage of moisture left in the soap bar or flake or granule can vary from 5% to 25%, without seriously affecting the non-disintegration properties, and yet be advantageous for solubility and dilution.

Solid synthetic detergents, likewise, can be converted and built into bars with regulated disintegration, independent of over-solubility of the active ingredient. Such synthetic detergents are chemically similar to fatty acid soaps and in their commercial form also have a hard crystalline phase and a softer non-crystalline phase. The present invention is therefore applicable to the conversion of such synthetic detergents in a manner similar to that of soap.

Aeration of bars or flakes or granules is a separate consideration not to be confused with the basic structure of the soap or synthetic detergent being aerated. The present conversion process, however, has important features favoring the problems of aeration. As a dispersion process for obtaining extremely fine particles of air or air cells the process surpasses any former method because the very thin layers (2 to 5 microns) as well as the enormous shearing and working forces which are applied to these thin layers govern the extent of dispersion. The better the dispersion the more permanent it is. Also, as the soap becomes tough with conversion, the air cells become more permanently impacted. Both of these effects make the problem of preventing de-aeration during extrusion much simpler. Bars of compacted ultra-microcrystalline soap may be su-ificiently aerated to provide a floating soap and synthetic detergents may have their density reduced by at least 10%. Furthermore, since aeration is developed in the product during formation of flake or powdered flake, such flake may form a commercial product.

It is therefore an object of the present invention to provide an improved process and apparatus for converting soap or similar plastic material into a compacted ultra-microscopic crystalline form.

Another object of the invention is to provide an improved process and apparatus for modifying the physical characteristics of soap, such as transparency and hardness, in which substantially all of the power required in the operation is utilized in breaking down soap crystals by attrition of a thin film of soap between relatively rapidly moving surfaces in a narrow slot under intense compacting and shearing forces developed by congestion of material in the slot.

A further object of the invention is to provide an improved process and apparatus for modifying soap in which effective control of aeration or de-aeration as well as temperature is easily accomplished while subjecting the soap to intense shearing and compacting forces.

Other objects and advantages of the invention will appear in the following description thereof made in connection with the attached drawings, of which:

Fig. l is a front elevation of milling apparatus in accordance with the present invention;

Fig. 2 is a side elevation of the apparatus of Fig. 1 with portions broken away;

aerated Fig; 3 1s an isometric detail of'the feeding.

shearing, compacting, aerating and discharging band-saw and' provided with driven band wheels.

I" and-2, for propelling a suitable metal band member- 3.

carrying the band 3. Plodder-type flake feeding devices t may-supply the material to be processed tofeed" chambers later described although the feeders-may be suitable pumps if thematerial.

being "converted is pumpable.

The band Wheels I and 2 are separated sufficiently to accommodate the feeding devices 6 and die slot members 1 and 8, each surrounding one straight stretch of the band. The members 1 and 8' may be jacketed or channeled as later described to distribute a coolant introduced at inlet -9and removed at outlet l0. Hoppers H and I2 receive the material to be processed, and hoppers l3 and M receive and deliver the material which has been: processed. The hoppers ll, l2, l3 and [4 are shown as being open, but can be made air-tight andcan be insulated, if necessary, to: prevent. loss of heat, volatile perfumes, or moisture. A: gas feeding orexhausting meansis illustrated at I5 and It, and may be used when desired to either augment or remove the entrained gas unavoidably brought into the apparatus' with the: fed material into hopper II or by the carrier-band 3.

Fig. 3 illustrates in more detail the elements of the die. slot member 8 and associated elements. The pl'odder 6 may include a worm I! within a barrel i8. The worm H may be driven from any suitable: variable speed source of power, not shown, connected to a shaft l9 so as to develop the properhyd-raulic feeding pressure on the material in a feed chamber of the die slot members. The die slot member 8 is made of a suitable metal, such as stainless steel, and is suitably constructed so as'to containa precisely :ma-

chined slot 2-! adjacent onefa'ce and extending longitudinally through the member. The slot 2| closely fits the band carrier 3. For example, on a model thisslot was fitted to within ts inch of the width of the carrier band 3 and to within ,4 inch of the thickness, for a band dimension of approximately %4 inch x inch. The band 3 was made'of mild steel such :as that used for bandsawing wood. Special clearances for this slot, at certain critical points, will be explained later. Cover plate 22 forms an air-tight wall on one side of the slot '2 l, and is arranged so that by removal, the :band 3 canbe replaced and the various chambers in the slot member 8 cleaned or examined with ease.-

At the entranceof the band carrier 3 the slot member 8 is provided with a labyrinth seal 23 closely fitting, the bandcarrier to prevent theescape'of material fed into chamber 20, under pressure. The labyrinth'seal providing stage-reduction of pressure between sealingstrips in conjunction with the inward travel of band 3 prevents any leakage from chamber 20. Revolving disc guides-24, shown in Figs. 1 and 2, bear against one edge of the--band3 to center the band The wheels may be mounted onv driven shafts 4- provided with crowned rims 5 in slot 21 and thereby eliminate any abrasion points where'bare metal parts have rubbing contact, thereby avoiding discoloration of the material being. processed.

Feeder Bis bolted in asuitable air tight manner to die member 8, for example, by flange 25' and delivers the-material to be-milled into the chamber 2-0 and into contact with the band '32 The die slot memberb' mayhavecoolant channels 25" so as to provide external metal walls and metal walls surrounding the die slot 2| and the various chambers in'the die slot member; 0001-- ant connections it and I0 communicate with the coolant channels'and the coolant channels may be provided with interconnections and suitable baflles, not shown, to provide for proper flow of coolant through the die slo't member. Carrier band 3 bisects the feed chamber 20 so that its edge is presented to the incoming flow of c'ompressed material. The hydraulic pressure o'f'this material, in chamber 20, is equally divided on the flat surfaces'of band 3 as well as the opposite edges thereof; This balances the pressures onthe band to allow the band to take the forces of the feed without being displaced in the die-slot.

The clearance of slot 2| at the feed point 26- at the lower portion of chamb'er20 may be increased and made slightly wedge shaped to facilitate adequate input to slot 2| .but not suflicient to overfeed andcause the mater'ial'to disgorge around band 3 at outlet 21 of the'slot-2'l. The flat sections of the 'slot,.su'ch as '26 and 28,

between small expansion chambers 29; will have of the slot, but will crawl along the surfaces thereof, for example, from one expansion chamloer29 to the next chamber during properly adjusted operation. In general, the last flat sec-- tion 36 should be somewhat longer than the other flat sections so as to withhold its coating.

These fiat sections, such as section 28, in conjunction with the traveling carrier band constitute an improved counterpart of the bite between two mill rollers operating at a differential in surface speed.

The small expansion chambers 29 preferably extend at an angle to theline of travel of band 3that is, generally crosswise of the band, and this angle will vary according to the consistency of the soap or other material so that the bulgedout coating on the band 3, as it emerges from compression in a flat portion of the slot, is trimmed upon its entrance to the next flat portion of the slot and the trimmings travel along the expansion chamber 29. Under these conditions, the material in the expansion chamber does not cake but'is kept in a turbulent condition and is redistributed over the surface of the band in the next fiat slot portions. The proper'number of flat slot zones, such as the portions 28, and expansion chambers 29, is dependent upon the properties of the particular material being processed.

The die slot member flis also preferably provided with oneormore stripping chambersinterrupting the slot2 I The stripping chamber 30 contains a .pair of stripping knives 31 secured to. the cover plate 22 nd engagingiopposite sides of from the band; carrier.

orifices 32 for introduction or withdrawal of gas or air. The functions of the stripping chamber will be discussed more in detail below. The soap or other material from the stripping chamber is then carried through the remainder of the slot 2| so as to pass through the additional expansion chambers 33 and the straight portion 34 of the slot. The milled material is then removed from the band carrier 3 by a pair of knives 35 as it emerges from the straight portion 8% of the slot.

Soap milling has heretofore involved the use of a series of sets of rollers each having two heavy mill rollers spaced approximately .007 in. apart to make a flake .008 inch thick. lhe rolls are driven so as to have their surfaces traveling in the same direction. Various speeds are employed but one roller usually has a surface speed of about 1,300 ft. per minute with the pick-up roller of the pair running approximately 7% to 8% faster, so as to develop a shear at the rate of approximately 100 ft. per minute on the soap passing through. This shear is exerted on a layer of soap approximately equal to the clearance .between rollers, or .007 in., which is approximately 175 microns and represents about the lower practical limit of clearances for roller mills. It is an extremely ineificient operation for abrading particles to a size of say 10 microns, for milled soaps, or micron for transparent-phase soaps. It means handling, at heavy squeezin pressures (500 lbs. per square inch), a soap layer that is 17 to 350 times s thick as the particles being developed by shear and pressure.

The apparatus of the present invention has a bite that is much more emcient for either milled soaps or ultramicrocrystalline soaps. The apparatus is operated so that no material disgorges around the band at the outlet 2'1, but instead all of the material is carried out as a coating on the band. The coating on the band is approximately .00068 inch in thickness. This has been found by test wherein 1 ounce of soap is carried out as a coating on an 4, inch band, coated on both sides, running 3,125 ft. per minute, every 2 minutes. This means that soap at a density of approximately .70, which is 2.47 cubic inches to the ounce, is being spread over 32,300 square inches of hand area, and therefore is approximately .00008 inch in thickness. This may vary up to .0002 inch, depending on the soap moisture, but it usually runs at an approximate dimension of 2 to microns. Transparent-phase soap requires much smaller particles than the figure of microns used for milled soaps. It must be converted to .1-.5 micron, depending on the material. The site in the present apparatus, which works on a carrier band coating of 2 to 5 microns thickness, at a shearing diiierential in speed of 3,125 ft. per minute, efficiently reduces the material into particles which will measure .5 micron. The apparatus of the present invention employs substantially all of the input power in useful shearing action in a confined space under high compacting forces. In contrast, the majority of the Work done in passing soap through a roller mill is Wasted in working the mass of soap in a manner not reducing the particle size even so far as developing lO-micron particles is concerned, and such a mill is not at all suitable for producing the much smaller particles of the transparent-phase soaps, namely, .1 to .5 micron. The crushing pressure of the rollers is not an important factor, because the small particles escape being crushed at such large clearances.

There is no direct method of calculating the compacting and shearing forces in the present apparatus but it is apparent that they are very high as shown by the translucency or transparency and hardness of the resulting soap. The transparency is an indication of a particle size less than a wave length of light and the hardness is an indication of intense compacting. These forces are produced by developing very high wedging pressures with the soap material itself as it iscarried along by molecular adhesion through the slot 2|. The wedging effectiveness of slot 2| depends upon the crowding or congesting of the material in the straight or flat sections, such as sections 26 and 28, by an overfeed from the previous feed chamber 20 or expansion chambers 29. so long as the coating on band 3 is active, rather than set into a layer that polishes to a hardness that escapes the drag of the expansion chamber 29 or the close-fitting straight sections 28, this effective wedging action is developed all along the length of slot 2|. It is the purpose of the strippin chamber 30 and its knives 3! to keep an inactive coating from developing. The number of stripping chambers, such as chamber 3%, which must be employed as well as the distances between stripping and expansion chambers to keep the straight sections of the slot at their peak of effectiveness will vary with difierent materials. Interchangeable die slot members which are easy to mount on the apparatus can be provided so that the proper die slot member can be employed for a particular material or the die slot member can be made in sections to enable various combinations or sections containing straight sections and chambers to be employed.

The stripping knives 3! within the stripping chamber remove all of the band coating and allow this stripped material to pass around the knives 3i and again feed onto the cleaned band as a new coating. The material in stripping chamber 30 may feed out as fast as it is stripped or it may pile up and develop a considerable hydraulic pressure, before the material will feed out as a new coating. In any case, since the soap films adhere to the metal band tenaciously, the stripping chamber 33 will operate at some developed pressure.

The stripping chamber 3i} serves another purpose, namely, for the aeration or de-aeration of the material. Gas supply means E5 or IE can be any suitable non-fouling arrangement of calibrated ormces 32, such as are described in my copending application, Serial No. 791,610, filed December 13, 1947, Figs. 7, 8, 9, 10, 17 and 18. A high gas pressure may be required with certain soaps, or especially synthetic detergent materials, and at the same time in relatively meager amounts, so that a minute, non-fouling, calibrated orifice means is required for orifices 32.

The conditions in the stripping chamber 30 are about the same as in the feed chamber 20 where the entrainment of gas normally takes place. However, certain soaps, such as milled soaps which are de-aerated and partially converted to a microcrystalline state, may not entrain sufiicient air in the feed chamber 29 alone to make them into a floating flake that can be integrated into a floating bar. Additional aeration may be accomplished in one or more stripping chambers 30, supplied with measured and pressure-regulated gas or air.

De-aeration, if desired, may be accomplished in one or more stripping chambers 30 by exhausting the accumulated gases therefrom through non-fouling, extremely fine orifices 32 with a vacuum pump attached to line 15. The stripping chamber 30 has the important feature of exposing a very thin film of soap, plus the breaking of gas cells by the stripping knives, so as to release this gas to the exhauster.

At the discharge end of slot member 8 the expansion chambers33 and straight sections 34 and 35 are arranged so that the over-feeding of this section by the preceding stripping chamber 33 is moderated by their elongation, so that no disgorging takes place at the discharge point 21. A test model, with dimensions described later, gave such results on several of the soaps tested. .If the straight sections as and 3B are elongated, a point will be reached, as is the case withany labyrinth. seal, where no material can makeits way'outexcept as a coating on the band 3, and this is the preferable operation.

.The final stripping knives 35 are shown in Eig.:-3.as not being enclosed,'so as to facilitate adiustmentandzrenewal of the knife edges. A dust cover only will usually be employed and the knives can 'berconstructed of a solid mounting whichtakes a renewable light blade. The test model, described later, used a flexible safety razor blade in a suitable mounting and was very satisfactory on a inch band 3. By staggering the. blades '50 that they contact spaced portions of the band. and adjusting the tension on the band 3,:a resilient arrangement is provided which minimizes the wear and abrasion of either the knife blade or the carrier band and provides a delicate running contact efiiciently removing the coating from the band.

As a'specific example, approximately 4 ounces of 17% moisture soap, made by the process of Mills Patent No. 2,295,594 was processed .in 10 minutes when :the carrier band was properly coated and no. disgorging around the band occurred at exit 2:1, using a %4 inch band (3), at 3,125, ft. per minute.

Excessive feeding pressure on chamber 20 causes soap'to disgorge around the bandt at exit 2'! in addition to that adhered to the band. This isnot a desirable operating condition, since best results are obtained when all of the discharge is carried out of the die slot by adherence to the band'B. The material will not be uniform in texture if part of the material is disgorged around the-band, since disgorged material is not sheared or. compacted to the same extent as that which is: coatedon the band 3. Furthermore, excessive powerisconsumed when disgorging takes place, due to cverfeeding and jamming of the'band t. Properly adjusted'feed will give a very uniform power demand.

-soap should'be softened by heating, if possible, to feed'at hydraulic pressure of to 15 lbs. per square inch, withinthe chamber 28. Cooler and hardersoap will, of course, feed at higher hyclraulic pressures, but these pressures may be. avoided by softening the soap with heat before feeding, without incurring any loss in milling effectiveness, since the cooling of the slot 2|. and the .band 3 restores hardness to the soap before occur .at the slightly elevated temperatures needed to get a-goocl feed at 5 to 15 lbs. gauge. This lower feed-pressure shortens the labyrinth gland lt, needed to seal the feed chamber'at the 10 blade entrance zone and places less strain on the band 3.

In addition to the cooling of the walls of the slot as described above, the band 3 may also be cooled. Some cooling of the band 3 can be accomplished by such expedients as supplying a coolant to the rims of the band wheels I and 2 through channels in the wheels and shafts 4 or by directing an air blast against the band before it enters the feeding chamber '20. However, it is advantageous in many operations to drastically cool the band. This may be accomplished by surrounding the band with cooled metal walls, for example, as shown in Figs. 4 and 5. As shown in thesefigures, cooling'chambers 37 made, for example of sheet metal, may be positioned on opposite sides of the band 3. Any suitable: coolant may be introduced through inlet pipes 38 and withdrawn through outlet pipes 39. That is to say, the cooling chambers may be the evaporator of a refrigeration system so as to produce any low temperature'desired. The cooling chambers 31 may replace one of the die slot members 1 or :8 in Figs. '1 or 2 or may be positioned adjacent the entranceof the band into a feeding chamber on the same straight section of the band :3 as a dieslot'member.

Even though die slot members I or 8', wherein conversion takes place, are cooled and the "temperature of the soap coatings on the walls of these slots is well regulated, itis'usually desirable to cool the band 3 itself. The thin film which carries through on the band despite the-congestion in the slot andchambers absorbs the shearing and compacting energies more than the thicker coatings on-the walls of the slot and the band 3 itself produces'a major temperature regulating effect on this thinactive film.

Test runs, for example, on 17% moisturesoap I fed at 100 F. both with and without band-cooling showed that cooling of the band more than doubled the conversion attained in the absence of such cooling. This improvement in conversion also provides a verificationof the fact that'the conversion of soft uncompacted soap to extremely hard compact structures is not a moisture-reduction effect. Some moisture loss can be e'x-' peeted from a-coatingonly 2 microns thick riding on a warm carrier band at high speed. Only nominalevaporation can occur in the short exposedzone around knives 35 if not enclosed 'by'a vapor proof cover and-this nominal amount will begreater with a warm'band than with a cold band, and therefore it is impossible to-explain the much greater hardness and transparency gained when a colder carrier band is employed except by conversion of the soap structure. The moisture reduction in the totally enclosablesys tem can be held to a negligible 'point and the great changes in hardness and transparency are obtained in tests run at 28% moisture, 17% moisture or 13% moisture andlower for thesoap fed into'the apparatus.

Band speed is an important factor governing the rate of feed, the particle size developed, the

hardness resulting from the compacting action, theamount of aeration, and'the thickness of the film or coating on the band 3. Bandspeeds ranging from approximately 3,000'to 8,000- ft. per minute are contemplated, a suitable speed being about. 6,000 ft. per'minute. It willbe apparent that the greater the:speed the greater the-capacity of the apparatus. Band width-also':in-

creases the capacity proportionately, and the;

greatest practical band width consistent withsuch limiting factors as problems of stripping knife performance, traction of driving pulleys, etc., will usually be employed. Both the down-travel of the band and the up-travel on the straight-away sections, if the structure is vertical, may be utilized. It is desirable to drive both the upper and lower band pulleys l and 2 to get sufficient traction as well as to hold the band 3 in line so as not to rub the edge of die slot 2!. The pulleys may be crowned in the conventional manner used for band-saws. A horizontal structure also Works satisfactorily and offers more accessibility in a battery unit, made up of several bands operating on one shaft.

The present process involves the intensification of shearing and compacting of materials by developing a very thin coating of the input material on the large surface afforded by a high speed carrier band and the shearing of this coating against the coating developed on the surface of a close fitting die slot through which the carrier band is caused to travel. The coatings are subjected to large wedging forces developed by the momentum of the coating on the band due to the high speed of the carrier band and the crowding of the slot with input material moved into the die slot and carried from stage to stage by the molecular forces of surface adhesion which are of a very high degree.

Soap introduced into the feed chamber can be made to adhere to the carrier band by regulating its stickiness with heat, and by the hydraulic pressure of the fed material in the chamber 20 forcing the soap against the surfaces of the carrier band 3 as it passes through the feed chamber. Melted soap requires little or no pressure to make it adhere to the carrier band. Soap heated as high as possible without reversion of the crystal formation will feed usually at 5 to lbs. pressure in the feed chamber. The lower the feed pressure, the smaller the labyrinth 23 need be around the carrier band at the entrance to the slot, and the less power required by the feeding means 6. Special texture and material considerations may require less heat and more hydraulic pressure to coat the carrier band satisfactorily. There is no mechanical limitation within reason on this feed pressure. By making the chamber 20 smaller, the drag on the carrier band 3 is minimized. The edge thrust on the carrier band may be offset by rolling guides 24! outside the feed chamber 20' so that the cantilever beam strength of the blade edgewise can withstand large hydraulic pressures in the chamber 20, if necessary. The labyrinth seal at the band entrance can be made extensive enough to step down the pressure and thereby seal and contain a material being fed at very high pressure, if necessary.

Once the carrier band is coated, that coating will carry into the die slot entrance stages, due to molecular forces of surface adhesion phenomena, and this coating will crowd the material ahead of it through the die slot 2!, stage by stage, so as to crowd against the carrier band within the slot and be carried through by the band, despite the shearing and compacting strength of the soap structure which resists it. Since the clearances are small and the gap is kept closed by the coatings themselves, there is developed a tearing and compacting action on even the smallest of the crystals. The transformation of the soap texture in tests of the model indicates that particles of approximately micron can be developed.

If the initial coating on the surfaces of the die slot straight section 28, etc., is allowed to cake and become polished by the fast moving coated band 3, the shearing and compacting affects such polished surfaces only and the balance of the material back of these surfaces escapes attrition. Also the throughput becomes very small. Such a condition is prevented by three factors.

The thickness of the coating on the band 3 may be made greater at the entrance to the slot than the thickness farther along the slot, thereby crowding the slot from the feed end all along and nearly to the exit 21. This crowding disrupts the coatings on both the surfaces of the slot 2| and the surface of the band 3. This may be accomplished by widening the entrance section of the slot, in contrast to the rest of the slot length, as well as by the hydraulic pressure in the feed chambers 25) or stripping chambers 38. 1

The expansion chambers 29 allow the compacted coating on the carrier band to bulge at the entrance into such chambers and thus a portion of the coating is trimmed off and churned along the slanted expansion chamber. This portion is forced back again onto the carrier band 3 as a new layer on the coating, thus disrupting th balance of the coatin by crowding and cross flow.

The knives in the stripping chambers 33 positively remove the coating from the carrier band 3 by mechanical means. The crowding action of the removed material again develops a hydraulic pressure in the enclosed stripping chamber 39 to cause the carrier band 3 to be recoated for the next pass into the slot 2|.

The number and spacing of the expansion chambers 29 and stripping chambers 30 is determined by the nature of the material and its consistency at the temperatures required to preserve the crystallization. On soap made according to Mills U. S. Patent No. 2,295,594, (Ivory) excellent conversion to the transparent phase was obtained by having 13 expansion chambers, followed by a stripping chamber, and 13 more expansion chambers, while on soap made according to Bodman Patent No. 2,215,539, (Swan) two interposed stripping chambers with fewer expansion chambers worked better.

The die slot member 8 can be opened and by carefully examining the material in the slot 2| and in th expansion chambers 29, it can be determined whether the coating is being sufiiciently disturbed, or whether it is tending to cake and clog such that the action of the band 3 is a surface polishing action only. Under balanced operation when material is not being disgorged from the die exit 27, the amount of power required is a useful index in arranging the number and spacings of the expansion chambers 29 and the stripping chambers 30. If no more power is required when the number of expansion chambers 29 is increased, their effectiveness is diminishing and a stripping chamber 38 should be interposed to strip and recoat the carrier band 3.

The carrier band 3 itself may be made of metal alloys which give better coating adherence with certain materials. Also, the flat surface of the carrier band 3 may be roughened to increase its pick up effect. These markings may, however, produce rapid wear of the stripping knives to shorten the life of the knife blade, so that if good adhesion can be gained by hydraulic feed pressure alone, that means is preferable.

Inaddition to the iactethaucrystal or texture refinement is; carried: :to :a, greater extent and accomplished at: higherefliciency .by "the :present process than in any prior art process, the. resulting .ultraemicrocrystalline soap; can 'be uniformly aerated during-the process to make .it float. This aerationis done onzextremely thin coatings so thatthe dispersion ofair or gas is uniform. The shearing and compacting, which ordinarily might be expected to squeeze out all of the as cells, cannot do so under the pressure developed in the slot by the rapidly moving band. The hearing acts as a gas dispersion means and the gas cells are retained despite the compacting. Should the speed of the carrier band 3 not be sufficient, or the hydraulic pressure on the feed be too great, or the temperature of the soap too .hi h o p rmit. entrainment of all the ir whichis necessary at the entrance tothe feed ham e 210', then. additional aerati n with xacteondi io for re lat on is. accomplished in the totally nclosed trip chambers, it alon the lengthof the member The feeding of this air into the chamber .is done at the most effective pressureby themounting offeeding orifices32, with non-fouling O enings, such as those disclosed in my application Serial No. 791,610, supra, wherein the orifice calibration is regulated bya restricting pin,.and the orifice around the pin is kept clean and unplugged by imparting motion to this pin in relation .to the orifice by means ,of any suitable reciprocating .drive. Such means can be used to introduce, small regulated amounts of gas at as high a pressure as is needed. Gas introduced. in a regulated manner to the stripping chamber 311' will be incorporated. in the coating in addition to any gas entrained with the feed in chamber 2i] until the correct finished density is reached to make a floating soap chip which later canbe integrated into a floating bar by several processes, such as those disclosed in my copending application Serial No. 791,610, supra, or Serial No. 129,093, filed November 23, 1949, which latter process involves, reducing the material to granular powdered form. and. then compacting the same into bars.

De-aeration is accomplished by reversing. the process. Whatever air is unavoidably entrained with the feed may be removedby placing a vacuum pump in communication with a stripping chamber or chambers '30 in a suitable arrangement in the entrance section of the member 8. Complete de-aeration depends uponthe exposure of yery'thinjfilms of aerated soap to the exhausted stripping chamber 31] and also, upon the strip! ping ofthesefllmsfrom the carrier band 3. Air which has beenimpactedin-an ultra-microorystalline, rubbery soap film is releasedmechanically ,by the spreading, and stripping action of the band 3 in the slot 2| and knives 3|. This enables the air to be removed so that the" resulting soap fiakeis clear when, it is finally strippedfrom thecarrier band 3. For de-aerati n, non-fouling and extremely small restricted orifices v32..I1 1ay beemployed toprevent clogging of the gas withdrawal channels or removal of soap with the gas. Such. orifices are afforded in accordance with the'disclosure inimy application Serial No. 791,610, referred to above.

Soap crystal reduction and compacting of the soap is best accomplished at ;the maximum carrier band speed possible within practical: limits and with minimum coating thickness; ,on the surfacesof the. slot ;21 andon thebandzil; In

7 J14 using the-present :processtfor .developing'sa .desired soapflake with respect-to dimensions and glossy finish, it is--preferableto .use, two stages in the operation. These stages may-be acrystal reduction. and compacting stage using a: very high speed band and close clearances and then asecond stageifor flake forming using aamuch slower speed and larger clearances in the discharge end of the slot 2|. The latter stage may be conducted in apparatus in which the slot clearance is gradually increased. A stripping chamber 30 may then be employed to produce a new coating on the band 3 whichis thicker than the desired flake. The last portion of the die slot may then be employed to reduce the thickness of the coating and polish the surface thereof rather than to disrupt the coating. The angle of knife 35, providing for the removal of the flake without causing it to be upset or wrinkled, also may be much smaller in the latter stage than is desirable for a high speed conversion operation. It is extremely difficult to avoid wrinkling of the flake unless the coating is increased to at least .001 inch.

One very advantageous factor in the finishing of flakes by the present process is the refined texture imparted in the shearing and compacting stage. The soap becomes waxy after processing through the die slot member 8 and. does. not resist removal from the carrier band 3 by the knives. 35. The surface of the flakenext to the band 3 as well as the surface next to the slot 2| areboth ironed to a sheen not possible heretofore, and-the waxy and tough character of the refined soap leaves it dust-free. The flakes do not easily break down into fines because of their rubbery nature.

Another. important; factor in the present process is the close temperature regulation which may be obtained. Heat is rapidly conducted through thewalls surrounding the die slot and the various chambers therein and such wallsmay be cooled throughout their length by any suitable cooling medium. It is apparent that the channels for'the cooling medium may be baflied or sectionalized so asto enable any desired temperature gradient to be maintained along the die slot. Also, the band may also be cooled as described above. Since the soap or other material being milled is formed into very thin coatings on the band and on' the surfaces of the die slot and these coatings are kept in a turbulent condition, heat may be rapidly extracted therefrom.

While the present process is primarily-a conversion operation, it lends itself to producing desirable solidification eifects; by heat regulation. For example, it is known that intense stirring during cooling of soap and other similar materials to produce crystals results in a different texture than cooling without agitation. Thus ultra-fine crystals can be produced by feeding the material at a temperature just above its solidification temperature and cooling and simultaneously working the material in the die slot. By simultaneously introducing air or other gas, aeration during solidification can also be accomplished. The process can therefore be employed. as an ultra-fine crystallizer for such materials as soap, ice-cream, shortening, eto'., either with or without aeration. Other materials such as face creams, synthetic detergents o r greases, etc, in semisolid form can be sub jected to-a conversion operation or they can be solidified in ultra-fine crystalline form with advantageous results.

The extent of intensification of the shearing and compacting efiects by this process is indicated in the following table, comparing the es- 16 2,215,539, four or five times under extremely high pressure through the same slot.

d. Compactness, determined by the force required to extrude the refined sample from this same die, was approximately 7 times that re- L) sential factors of conventional soap milling, done quired on original soap fed to the process. with water-cooled rollers, with the present proce. A de-aerated sample of thls refined product ess: was retreated at the same band speed, but fed Rollers Present Comparison Thickness of soap fluke sheared and 0.008 0.00008 yioo.

discharged from process. Number of passes through bitc 1 2.550 1H tlmes. Distance of flake travel between parses 3 Shearing rate in bite 3,0006,0 00 ft. 30-60 tlnles.

per mm.

The following data on test runs of a model at 130 F. and removed at 120 to 130 F. This of this process will serve to evaluate its great was converted further so as to be more transeffectiveness as a crystal reducer and compactor, lucent and much more compacted, so that apdespite the presence of air cells: proximately 15 times the pressure was required I! I! t i fed 17% moisture, aera to d to force It through a x Slot' grillsrocess soap. f. A test run of un-aerated, 13% moisture Temperature of feed f g gg ggg f needed milled soap having an 80% tallow and 20% TejIil'lllielittule or discharged 95 to 110 F. coconut oil base (Camay) yielded a product with are. Pressure in feed chalnber Approximately 10 lbs. per texture to double mlnlng of aerated square Inch gauge. 1'7 moisture Mills-process soap (Ivory). Soap Dimensions of carrier band 80 /1Il. 100tll'h; ci /c4 1n. wide; Was fed at F and discharged at 1200 to 2 in. l L Metal in earrier band Mild? steel Wood-saw blade 130 F., and required the use of one strlpplng Speed of carrier band 3 gg l gg 0m chamber and some additional air to make the Power required Less than horsepower. finished flakes float. Dimensions of slot nlemb r A z/hlll. hexalgo llal plefg of This new process is particularly applicable to s ee in. ng, with a lengthwise slot the ultra-refinement of soaps. However, many g g y g g 3;; other applications are possible using the same with 3 in, p nanow general principles which govern its efiectiveness est Placeson soap For example tooth pastes can be re- Ex ansion chambers, number 13, s aced evenly with I Emma i of stflaiglfiit fi h f duced to a colloidal and de-aerated state in this ween eac ac 0 amb d in ber drilled with drlll at angle of 25 0 1 a per- 40 Shaving creams or powders, made from m1crogg fg crystalline soap bases, can be refined into with alternating slopes up products with better lathering properties or size of feed chamber ant; dlgvyllLx 5 long 1nd better textures. Also, face creams of superior Placed at texture can be obtained.

angles to edge of Synthetic detergent chips, both those containfiat tof flake g 131 lbsjperlyhour, 7 4:) ing the salts incident to their chemical processing l 015 ure in conver e are" etween 5 and 7 n Density of aerated refined Floats in water at room a g g these saltsican aerated.and com flake, tempemtturey with? E pale e and coollng 1s partlcularly important 0 a s r pp g 0 mm w en low melting point synthetic detergent bases or mammal are being aerated. Tests on a sulfated' mono- Textme glyceride synthetic without band cooling gave poor conversion as measured by transparency i fiif were f l de'aeatmg gand hardness of the processed material. How- P 9 1 P 3f 4 Ounce lf g ever, with a cooled band entering a cooled the slot i i (11311 maimg g g i' F2 thlck') chamber the conversion was very pronounced. s 32 22 5 1 5? s g ig a g; Translucency of a high order developed and the converted material was 3 to 7 times harder than stamp dle surface. The orlglnal soap sticks to the original material subse uent inte tbls dle very tenaclously t t q gr Ion m I s o aera ed bars may be accomplished by the proco & o

a when for cold- Water ess disclosed ln my copendlng application, Serial welding with another similar tablet, and re- 129,093 fil d November 23 1949 now Patent peatedly washed with water, revealed a water- No 2594958 issued April 29 5 weldtngy property equal to adultemted Special greases, requiring a blend of converted meiclal i g w 511911 as Muhlens N soaps with petroleum products, can be benefited 471i. Cracks heal in use, nstead of growlng by the present process, this being a typical am Worse as t do on C-Onventwnal mwrocrystalc5 plication in which the soap ingredient is assistllne 2 1i mllfiid s oapsd t t h b ing another ingredient with less molecular sur- 0. ace in lame er ex ruslon 0 am er face adhesion to metaL with exit die slot around circumference which It will be apparent that the present apparatus measures 1.57" x .001", and extruded as an constitutes an efilcient colloidal dispersion mill intensely compacted film Under 1 e useful for many applications where intense flake revealed a transparency which is comparshearing and compacting fomes are required able to an ultra-micro-crystalline soap which ticularly where controlled temperature condiwas made by extruding and re-extruding an tions are also required. unheated sample of Swan soap, i. e. soap I claim; made by the process of the Bodman Patent No. 1. The method of converting soap by mechanical manipulation thereof while in asolid state, which comprises: forming the solid soap-into a ribbon not more than ontheorder of one sixtyfourth of an inch thick; passing the ribbon of soap lengthwise through a shearing and compacting zone; imparting motion to the surface layer of soap at one side of, the ribbon as it moves through said zone, relative to but parallel with the surface layer of soap at the opposite side of the ribbon, to effect subdividing and compacting of the particles in the mass of the soap comprising said ribbon; successively and repeatedly turbulently spreading and congestin the ribbon of soap as it moves through the shearing and compacting zone to thereby intensify the conversion; and maintaining the temperature of the soap undergoing conversion below the crystalline reversion point of the soap.

2. The method of mechanically refining. and aerating soap and similar material, which comprises: forming the material into a plurality of film-like sheets not more than on the order of one sixty-fourth of an inch thick; force feeding a plurality of such sheets edgewise in one direction through a shearin and compacting zone with the sheets in side-by-side parallel relationship; introducing air into said zone; in said zone imparting high speed motion to the surface layers of the material at the inner sides of the sheets relative to and substantially parallel with the surface layers of the materialat the outer sides of the sheets, and simultaneously effecting high speed internal churning of the mass of material comprising each of said sheets so asto effect subdividing and compacting of particles throughout the mass of material comprising each sheet, and occlusion and fine dispersion of air throughout the mass of material comprising the sheets; and maintaining the temperature of the material undergoing refinement below the crystalline reversion point of the material.

3. An attrition mill, comprising: an endless movable band havin opposite substantially fiat sides; means constraining the band for lengthwise travel of a stretch thereof in a straight line path; a stationary member at each side of said straight stretch of the band having a milling surface spaced slightly from the adjacent flat side of the band; means for feeding material to be milled edgewise against the band and into said spaces between said surfaces of the stationary members and the sides of the band; and means for driving said band at high speed.

4. The apparatus set forth in claim 3, further characterized by the fact that said stationary milling members each have a'series of spaced apart congestion grooves therein opening to and extending across their milling surfaces generally crosswise of the path of travel of the movable milling element.

5. An attrition mill, comprising: an endless movable band constrained to lengthwise travel in one direction; means defining a milling chamber through which the band travels, said chamber having walls embracing the stretch of the band traveling through the chamber and provided with elongated milling surfaces between which the band moves with very close clearance at each side, which clearances together constitute the attrition zone of the mill, said chamber having an inlet positioned to direct material against the edge of the band and an outlet downstream therefrom with respect to band movement; means for forcibly feedin material to be milled into the milling chamber through the in- 18 let thereof to fill said attrition zone; and means for driving the band athigh speed in, a direction to cause it to travel from the inlet of the milling chamber toward the outlet thereof and whereby the travel of the band and the force feeding the material into the milling chamber coact to effect movement of the material through the attrition zone and to subject the material to intense. shearing and compacting forces before it reaches the outlet of the milling chamber.

6. The attrition mill of claim 5 further characterized by the fact that said chamber walls have grooves therein opening to their milling surfaces and extending obliquely across said surfaces. r

'7. The attrition mill of claim 5 further characterized by the provision of scraper means acting upon the band as itleaves the milling chamber for removing milled material from the band.

8. Theatt-rition mill of claim'5 further characterized by the fact that said endless band is relatively thin and flexible, has flat opposite sides, and is constrained to travel with a stretch thereof moving in a straight line path; and further by the fact that the milling surfaces between which the band travels are fiat and overlie the straight stretch of the band, said surfaces having a length several times the width of the band so that particles in the mass of material'moving through said attrition zone are subjected to shearing and compacting forces a plurality of times before reaching the outlet of said chamber.

9. An attrition mill, comprising: an endless movable metal band; means constraining the band for lengthwise travel along a straight line path; means defining an attrition chamber having side walls spaced apart a distance slightly greater than the thickness of the band; means mounting said attrition chamber across said straight line path of the band with the band extending through the chamber and positioned between the side walls thereof; means for feeding material to be milled into said chamber; means for driving said band at high speed; and means for cooling the band;

10. Milling apparatus of the character described, comprising: aflexible carrier band; means mounting the band for movement thereof along a straight line path; a milling chamber embracing the band as it travels along said straight line path, said milling chamber being closed except for inlet and outlet openings in opposite walls thereof through which the band passes, and an inlet opening forthe material to be milled; the interior of said chamber being shaped to provide a feedihg'zone communicated with the inlet openin and a milling zone, the walls of the feeding zone being spaced from the edges as well as the sides of the band, and the milling zone having side walls closely fitting the opposite sides of the band; and means for feeding the material to be milled under pressure into said feeding zone.

11. The method of mechanically refining solidified soap to raise its viscosity and at the same time increase its solubility, which comprises: moving a pair of coacting wall surfaces across one another with substantial areas thereof at all times in opposition and substantially uniformly spaced apart a distance on the order of not more than one sixty-fourth of an inch to define a thin shearing and compacting zone having relatively moving walls of substantial area; applying pressure upon the soap in the solidified state and thereby forcing the soap as a filmlike sheet into the shearing and compacting zone with the pressure on the soap sufiicient to have it fill said zone; by said pressure and the relative movement between the opposed wall surfaces forcing the film like sheet of material through and from the shearing and compacting zone and thereby effecting relative movement between that portion of the film likesheet of soap contiguous to one of the wall surfaces and that portion thereof contiguous to the other wall surface; so regulating the speed at which the opposing wall surfaces move with respect to one another that said relative movement between the portions of the film like sheet of soap at the opposite sides thereof effects intensified shearing and compacting of the soap manifested by increased viscosity and solubility; and maintaining the temperature of the soap undergoing refinement below the crystal line reversion point of the soap.

12. The method of mechanically refining solidified soap and similar plasticizable material which is capable of being softened by heat and has a crystalline phase capable of being broken down to an ultra-microcrystalline particle size, which comprises: moving a pair of coacting wall surfaces across one another at a speed of at least on the order of 3000 feet per minute with substantial areas of the wall surfaces at all times in opposition and substantially uniformly spaced apart a small fraction of an inch to define a thin shearing and compacting zone having relatively moving walls of substantial area; applying pressure upon the material in its solidified state and thereby forcing the same as a film-like sheet into the shearing and compacting zone with the pressure upon the material sufficient to have it completely fill said zone; by said pressure in coaction with the relative movement between the opposed wall surfaces forcing the film-like sheet of material through and from the shearing and compacting zone and therebyefi'ecting relative movement between that portion of the material at one side of the film-like sheet and that portion thereof at the other side of the sheet, which relative movement effects an intensified shearing and compacting of the material; and maintaining the temperature of the material undergoing refinement below the crystalline reversion point of the material.

13. The method of claim 11 further characterized by feeding an ingredient compatible with soap into the shearing and compacting zone along with the soap.

14. The method of mechanically refining solidified soap and similar plasticizable material which is capable of being softened by heat and has a crystalline phase capable of being broken down to an ultra-microcrystalline particle size, which comprises: passing a carrier element having opposite surfaces of substantial area between a pair of facing wall surfaces which also-have substantial area, with a substantial area of each of said surfaces of the carrier element at all times opposite and substantially uniformly spaced from the adjacent one of said pair of facing wall surfaces a distance on the order of not more than one sixty-fourth of an inch to define a pair of side-by-side thin shearing and compacting zones each having relatively moving walls of substantial area; applying pressure upon the material in its solidified state and thereby forcing the same as film-like sheets simultaneously into both shearing and compacting zones with the pressure upon the material sufficient to have it completely fill both zones; by said pressure and the movement of the carrier element forcing the film'- like sheets of material through and from the shearing and, compacting zones and thereby effecting relative movement between the surface layers of material at opposite sides of each filmlike sheet, which relative movement effects an intensified shearing and compacting of the material; and maintaining the temperature of the material undergoing refinement below the crystalline reversion point of the material' 15. The method of claim 14 further characterized by the step of removing the material adhering to the surfaces of the carrier element as they pass from between the pair of facing wall surfaces.

16. The method of claim 14 further characterized by the fact that the maintenance of the temperature of the material undergoing refinement is effected by cooling the carrier element outside the shearing and compacting zones.

17. The method of claim 14 further characterized by the step of so balancing the speed of the carrier element and the pressure upon the mate rial that the material leaves the shearing and compacting zones along with and substantially at the speed of the carrier element.

18. Soap which has been mechanically refined by the method set forth in claim 11.

DONALD E. IWARSHALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 405,177 Quenehen June 11, 1889 702,933 Edwards June 24, 1902 2,215,539 Badman Sept. 24, 1940 2,417,495 Houlton Mar. 18. 1947 OTHER REFERENCES Tjutjunnikov, Article in Seifenzeider Zeitung, 1941, vol. 68, pg. 193, 

